Call control system, call controller, terminal device, and call control method

Abstract

There are provided a call control system, a call controller, a terminal device, and a call control method capable of selecting an optimum communication network without overly complicating the configuration of the terminal device and the call controller. A call controller accesses information representing present conditions including a failure of a communication network held in a communication network present condition data holding unit, and information held in an applicable priority order data holding unit on the terminal device and which is information of the priority order for communication network selection acquired and held in the call-originating side information acquiring and holding unit on the call controller side. A call control unit on the call controller side selects an optimum communication network for setting up a call.

1 . A call control system including:
 a call controller for controlling a call by selectively using a plurality of communication networks; and a plurality of terminal devices applicable in the plurality of communication networks,   the call controller comprising:   a communication network present condition monitoring unit for monitoring present conditions of the plurality of communication networks and acquiring through the monitoring communication network present condition data representing the present conditions of the communication networks;   a communication network present condition data holding unit for collecting the network present condition data acquired by the communication network present condition monitoring unit and holding the collected data in a storage medium;   a call-originating side information acquiring and holding unit for receiving a call-originating request from a terminal device on a call-originating side, and acquiring and holding applicable network data representing an applicable communication network for setting up the call in an area where the terminal device on the call-originating side is located, and available network data representing a communication network which the terminal device on the call-originating side can utilize, the applicable network data and the available network data being included in the received call-originating request; and   a call control unit for controlling the call based on the applicable network data and the available network data held in the call-originating side information acquiring and holding unit, and the communication network present condition data held in the communication network present condition holding unit upon reception of the call-originating request from the terminal device on the call-originating side, and   the terminal device comprising:   an applicable priority order data holding unit for holding applicable priority order data that represents a priority order for selection of the communication network applicable for setting up a call in compliance with the call-originating request; and   a terminal side call control unit for sending the call-originating request to the call controller in accordance with external manipulation, starting call setup processing for use of the communication network in the priority order based on the applicable priority order data held in the applicable priority order data holding unit, and upon reception of an application change notice of applying another communication network other than the communication network in the priority order based on the applicable priority order data held in the applicable priority order data holding unit, stopping the call setup processing, and sending the call-originating request under a condition of applying said another communication network in accordance with the application change notice.   
     
     
         2 . The call control system of  claim 1 , wherein the terminal device is configured so that the terminal side call control unit sends the call-originating request attached with a call identifier for specifying one call, and
 the call controller is configured so as to identify the one call by the identifier attached to the call-originating request from the terminal device.   
     
     
         3 . A call controller applicable to a call control system comprising: the call controller for controlling a call by selectively using a plurality of communication networks and a plurality of terminal devices applicable in the plurality of communication networks; the call controller comprising:
 a call control communication unit for communicating with an outside;   a communication network present condition monitoring unit for monitoring present conditions of the plurality of communication networks and acquiring through the monitoring, communication network present condition data representing present conditions of the communication networks;   a communication network present condition data holding unit for collecting the network present condition data acquired by the communication network present condition monitoring unit and holding the collected data in a storage medium;   a call-originating side information acquiring and holding unit for receiving a call-originating request from a terminal device on a call-originating side, and acquiring and holding applicable network data representing an applicable communication network for setting up the call in an area where the terminal device on the call-originating side is located, and available network data representing a communication network which the terminal device on the call-originating side can utilize, the applicable network data and the available network data being included in the received call-originating request; and   a call control unit for controlling the call based on the applicable network data and the available network data held in the call-originating side information acquiring and holding unit, and the communication network present condition data held in the communication network present condition holding unit upon reception of the call-originating request from the terminal device on the call-originating side.   
     
     
         4 . The call controller of  claim 3 , wherein the call-originating side information acquiring and holding unit and the call control unit are configured so as to identify one call by a call identifier attached to the call-originating request from the terminal device. 
     
     
         5 . A terminal device appropriate for a call control system comprising a call controller for controlling a call by selectively using a plurality of communication networks and a plurality of terminal devices applicable in the plurality of communication networks, the terminal device comprising:
 an applicable priority order data holding unit for holding applicable priority order data that represents a priority order for selection of a communication network applicable for setting up the call in compliance with a call-originating request; and   a terminal side call control unit for sending an call-originating call request to the call controller in accordance with external manipulation, starting call setup processing for use of the communication network in the priority order based on the applicable priority order data held in the applicable priority order data holding unit, and upon reception of an application change notice of applying another communication network other than the communication network in the priority order based on the applicable priority order data held in the applicable priority order data holding unit, stopping the call setup processing, and sending a call-originating request under a condition of applying said another communication network in accordance with the application change notice.   
     
     
         6 . The terminal device of  claim 5 , wherein the terminal side call controller is configured so as to send the call-originating request attached with a call identifier for specifying one call. 
     
     
         7 . A call control method for a call control system including a call controller for controlling a call by selectively using a plurality of communication networks and a plurality of terminal devices applicable in the plurality of communication networks, the call control method comprising:
 in the call controller,   a communication network present condition monitoring step of monitoring present conditions of the plurality of communication networks and acquiring through the monitoring, communication network present condition data representing present conditions of the communication networks;   a communication network present condition data holding step of collecting the network present condition data acquired in the communication network present condition monitoring step and holding the collected data in a storage medium;   a call-originating side information acquiring and holding step of receiving a call-originating request from a terminal device on a call-originating side, and acquiring and holding applicable network data representing an applicable communication network for setting up the call in an area where the terminal device on the call-originating side is located, and available network data representing a communication network which the terminal device on the call-originating side can utilize, the applicable network data and the available network data being included in the received call-originating request; and   a call controlling step of controlling the call based on the applicable network data and the available network data held in the call-originating side information acquiring and holding unit, and the communication network present condition data held in the communication network present condition holding unit upon reception of a call-originating request from the terminal device on the call-originating side, and   in the terminal device,   an applicable priority order data holding step of holding applicable priority order data that represents a priority order for selection of the communication network applicable for setting up the call in compliance with a call-originating request; and   a terminal side call control step of sending an call-originating request to the call controller in accordance with external manipulation, starting call setup processing for use of the communication network in the priority order based on the applicable priority order data held in the applicable priority order data holding unit, and upon reception of an application change notice of applying another communication network other than the communication network in the priority order based on the applicable priority order data held in the applicable priority order data holding unit, stopping the call setup processing, and sending a call-originating request under a condition of applying said another communication network in accordance with the application change notice.